STAT6 Loss in Dedifferentiated Solitary Fibrous Tumor

Schneider, Nina; Hällin, Magnus; Thway, Khin

doi:10.1177/1066896916650257

Cited by 28 publications

(23 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Two dedifferentiated SFTs had the typical strong and diffuse nuclear staining in the dedifferentiated areas, 6 were focally positive, and 3 had complete loss of expression. A similar finding was reported by Schneider et al 18 in which there was diffuse strong nuclear expression of STAT6 in the conventional and malignant regions of the tumor, but the dedifferentiated region had complete loss of expression. However, Kurisaki-Arakawa et al 13 presented a case in which the high-grade area of dedifferentiated SFT lost expression of CD34 on IHC but retained expression of NAB2 and STAT6.…”

Section: Gross/microscopic Featuressupporting

confidence: 88%

Dedifferentiated Solitary Fibrous Tumor: A Concise Review

Olson¹,

Linos

2018

Archives of Pathology &Amp; Laboratory Medicine

View full text Add to dashboard Cite

Solitary fibrous tumor (SFT) is a unique mesenchymal neoplasm that was originally believed to be of submesothelial origin. Eventually, SFT expanded to include what was previously called hemangiopericytoma in other regions of the body that had similar immunohistochemical and morphologic features. Although most are benign, many studies have tried to identify histologic features that predict which tumors will behave in an aggressive manner. Recently, dedifferentiation has been described in rare cases of SFT and does appear to correlate with a more aggressive clinical course. Dedifferentiated SFT occurs in a similar age range and location as conventional SFT and can resemble multiple different malignant entities. Utilization of ancillary studies and thorough tissue sampling is important to reach the correct diagnosis. The morphologic features, immunohistochemistry, molecular alterations, and prognosis will be discussed.

show abstract

Section: Gross/microscopic Featuressupporting

confidence: 88%

Dedifferentiated Solitary Fibrous Tumor: A Concise Review

Olson¹,

Linos

2018

Archives of Pathology &Amp; Laboratory Medicine

View full text Add to dashboard Cite

show abstract

“…Therefore, although STAT6 immunohistochemisty correctly identifies all conventional and malignant SFTs, it is not always detected in the dedifferentiated component [23]. RT-PCR may be helpful in such cases since the NAB2/STAT6 fusion is retained in all STAT6-negative dedifferentiated tumors [23, 24]. The immunoprofile in our case showed retained expression of CD34 and STAT6 and there was no overexpression of p53 or p16 in the dedifferentiated component.…”

Section: Discussionmentioning

confidence: 81%

A dedifferentiated solitary fibrous tumor of the parotid gland: a case report with Cytopathologic findings and review of the literature

2019

View full text Add to dashboard Cite

Background Solitary fibrous tumor (SFT) is a ubiquitous mesenchymal neoplasm but it rarely occurs in the parotid gland. The histological features are variable, with the majority having spindle cell morphology and non-specific branching (staghorn) ecstatic vascular pattern. SFT ranges from benign to overtly malignant. Dedifferentiation within SFTs represents an abrupt transition from a well-differentiated component to a high-grade area, the latter most often including poorly differentiated epithelioid/round cell or high-grade spindle cell morphology. To the best of our knowledge, dedifferentiated SFT in the parotid gland has not been previously reported. Case presentation A 33-year-old woman presented with a soft tissue tumor in the right parotid gland that had been present for 6 months. Fine needle aspiration (FNA) cytology indicated epithelioid morphology in the dedifferentiated component of the tumor, along with metachromatic myxoid matrix. The tumor was initially interpreted as a salivary gland neoplasm of uncertain malignant potential (SUMP).Right partial parotidectomy was performed, and microscopic examination of the resected specimen revealed a malignant spindle cell tumor with a central epithelioid/anaplastic component. The tumor cells were diffusely positive for CD34, STAT-6 and FLI-1, and negative for pan-cytokeratin, CAM5.2, p63, S100 protein, CD31, SMA, and calponin.ERG and Ki67 immunostaining showed an accentuated nuclear staining pattern in the central dedifferentiated area. There was no overexpression of p53 or p16. The patient is currently undergoing regular follow-up and is 11 months postresection with no evidence of recurrence or distant metastasis. Conclusions Unlike the typical spindle cell morphology of conventional SFTs, malignant SFTs can show areas of dedifferentiation mimicking an epithelial neoplasm. FNA of dedifferentiated SFTs of the parotid gland may show, a combination of atypical epithelioid cells and metachromatic myxoid/collagenous matrix, which is a less emphasized cytological feature of SFT and may lead to misdiagnosis as a more common parotid gland epithelial neoplasm.

show abstract

“…found that immunohistochemistry and western blot analysis indicated that chimeric protein expression was atypical or absent in nine out of 11 dedifferentiated tumors. This suggests that the loss of STAT6 is related to the dedifferentiation of the SFT …”

Section: Discussionmentioning

confidence: 97%

Malignant solitary fibrous tumor occurring in the mediastinal pleura showing NAB2ex4‐STAT6ex2 fusion and negative STAT6 immunohistochemistry: A case report

Zhang

Xiong

et al. 2020

Thoracic Cancer

View full text Add to dashboard Cite

Solitary fibrous tumor (SFT) is a rare clinical tumor, defined as a mesenchymal tumor of fibroblastic origin. A classic SFT is benign in most cases, but its clinical behavior is unpredictable. Lately, molecular analyses has discovered that almost all SFTs harbor an NAB2-STAT6 fusion gene, which is considered specific to this tumor type. Recent studies have suggested that nuclear STAT6 immunoreactivity is a highly sensitive and specific marker of SFTs and can be helpful when diagnosis is inconclusive by conventional methods. We herein report the case of a rare malignant solitary fibrous tumor occurring in the mediastinal pleura. An 82-year-old Chinese man with intermittent breathlessness was referred to our hospital. Chest CT showed a significantly enhanced irregular huge soft tissue mass in the anterior mediastinal area. After radical resection, the immunohistochemistry staining results of the sample showed that STAT6 was negative. The final diagnosis was confirmed by qualitative endpoint reverse transcriptasepolymerase chain reaction technique, showing positive NAB2ex4-STAT6ex2 fusion.

show abstract

STAT6 Loss in Dedifferentiated Solitary Fibrous Tumor

Cited by 28 publications

References 14 publications

Dedifferentiated Solitary Fibrous Tumor: A Concise Review

Dedifferentiated Solitary Fibrous Tumor: A Concise Review

A dedifferentiated solitary fibrous tumor of the parotid gland: a case report with Cytopathologic findings and review of the literature

Malignant solitary fibrous tumor occurring in the mediastinal pleura showing NAB2ex4‐STAT6ex2 fusion and negative STAT6 immunohistochemistry: A case report

Contact Info

Product

Resources

About